I can’t figure out why I can’t call figma.ui.postMessage inside the figma.ui.onmessage method. If I call the postMessage method outside the onmessage method my EventListener gets the message. But if I use postMessage like this I don’t receive the message. What am I doing wrong?

figma.showUI(__html__, { themeColors: true, height: 300 });



figma.ui.onmessage = (msg) => {

  figma.ui.postMessage("Test");

  figma.closePlugin();

};

The App.tsx file looks like this:

import React, { useRef } from "react";

import "./App.css";

import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";

import { faFileExport } from "@fortawesome/free-solid-svg-icons";



function App() {

  const onCreate = () => {

    const count = 5;

    parent.postMessage(

      { pluginMessage: { type: "create-rectangles", count } },

      "*"

    );

  };



  window.addEventListener("message", (event) => {

    const data = "Test data";

    const blob = new Blob( data], { type: "text/plain" });

    let file = URL.createObjectURL(blob);

    let a=document.createElement('a');

    a.download='mydata.txt';

    a.href=file;

    a.click();

  });



  return (

    <main>

      <header>

        <h2>Test</h2>

      </header>

      <footer>

        <button className="download_button" onClick={onCreate}>

          <FontAwesomeIcon icon={faFileExport} />

        </button>

      </footer>

    </main>

  );

}



export default App;